Continuous extraction and filtration apparatus



Deco 19, 1933.. P. 1.. mum 1,940,585

CONTINUOUS EXTRACTION AND FILTRATION APPARATUS Filed May 29. 1930 I 2 SheetsSheet l Dec. 19, 1933. R U' 1,940,585

CONTINUOUS EXTRACTION AND FILTRATION APPARATUS Filed May 29, 193o zsheets-sheet 2' 25 On the other hand,

. Patented 1 9,

emu-D amas OON'IINUOllS EXTRACTION FILTRA- TION APPARATUS PhillppLorenI Fauth, Wiesbaden, Germany Application May 29, 1930, Serial No; 457,224, and

' 1 in Germany June 14, 1929 Heretofore valuable extracts of oil-containing material, such as seeds or the like, and miscellaneous filtration has generally a special apparatus. In prior practice, however,

ii there has been the defect that the extraction has taken place in a continuous manner while it has not been possible to carry out continuous. filtration because the filter used always remained entirely operable only for a limited time and it was necessary torenew it from time to time. This,

however, considerably of the process.

Apparatus for this purpose having drum bodies which rotate in a cylinder which is partially lowers the practicability 7 1 filled with solvent have been known. Here, however, there is-a washing without a continuous operation because a simultaneous removal 0! the extracted material does not occur.

It has already been proposed, to conduct the extraction material to the solvent by means of screw conveyors. Here it has beenshown that the material conveyed in a stationary spiral trough clogs the stationary filter bottom of the trough after a short-period or operation.

filter cloths, tin sieves,

porous stone, etc., heretofore used cannot be employed for, continuous filtration, because, for

example, cloths absorb moisture in a short time and become impenetrable, while sieves, although remaining penetrable, cannot give a clear filtrate, and rotating porous stones permit the passage only of liquids, when they are-so coarsely porous that a clear filtrate cannot be obtained.

It the grains, however, are so fine that a clear 3 filtrate is possible, a rotating stone permits passase of nothing-at all. 1 The new apparatus according to thisinvention. consists 0! a rotating drum divided into two subdivisions by meansoi a restriction. In the first part or the I treated is 'saturated witli solvent, while in the second part or the drum it is filtered and washed.

Longitudinally of the drum extends a rotary partially hollow shaft which serves as an inlet 5 for the solvent to the interior of the drum. The shaft supports screw conveyors which movethe extraction material from a, stationary trough provided with an inlet hopper first to the saturating or enriching drumand then to the filtering. which it reaches the and washing drum, from outlet of the apparatus.

On the inner walls 0! ing to the invention,

the drum body, accordthe drums. I L

The shaft and two part drum body have separate drives, the relative speeds of which can be adjusted as required. In this way regulation oi the period of saturation of the extraction mabeen effected in Y traction material can thus be drum the material to be spirals are mounted whichv55 intimately mix the material and move it through .blades 9 terial' with solvent, as well as of the extraction,

is made possible. i

Use or a saturating drum, as opposed to known feeding spirals, afiords the important advantage that the extraction material comes into intimate contact with the solvent, whereby solution of the oil or fat is favored. The restriction at the junction of the two drums results in maintaining a certain condition of solvent in the enriching drum such that a continued repeated of the material with solvent occurs. This is not possible with a screw conveyor, because --its helical trough must always have its outlet on the bottom.

In addition, according to .the invention, the casing of the filter drum is covered with an antimoisture impregnated silk for filtering. This filter covering absorbs no moisture whatever and thereforeneed not be changed, whereby an entirely continuous operation is made possible.

The filter drum is surrounded by a stationary casing which catches'the filtered miscellaneous matter, and conveys it through an outlet to the distilling means. r

The modified Iorm of filtering and extrac Ii drum, as shown in Figs. 4 and 5, is subdividj into several compartments by constrictions the insertion of partitions. The successively ar ticulated drum compartments makes possible repeated washing of the material in the individual compartments and to appreciably raise the emciency of the filtratio The solvent and exexposed to each otherin a counter current.

In this modification oi thedrum, the material being treated (seeds or the like) andthe. solvent remain in intimate contact for a considerable period, which tends to increased'econonly. a The invention is hereinafter descrlbed by way of example, with reference to the accom diagrammatic drawings in'which:

Figure l is a longitudinal section illustrating one construction of apparatus according to the invention. Figures 2 and 3 are sections along the lines I--I, and II-II respectively of Figure 1. Figure 4 is a longitudinal section illustrating a modification, and Figure 5 is a section on the line lII-lII oI-Figure 4.

In carrying the invention into effect and with reference to Figures 1 to 3 o! the accompanying diagrammatic drawings, the rotating member consisting of the two drums 1 and 2 is mounted in the bearings 3, 4 and 5, and is driven by the driving pulley 6. A stationary casing '1 having a discharge pipe 8 surrounds the drum 2. Helical and 10 are fixedtotheinner walls of the drums 1 and 2. The circumference of the drum 2 is-constructed in the form oia filter 11, 120

which consists of separate frame parts, for example of four parts, 12a to 12d, as shown in section in Figure 3, covered with silk impregnated against moisture.

A partially hollow rotatable shaft 15 is disposed co-axially with the rotating members 1 and 2, and is mounted in the bearings 13 and 14, which shaft 15 is driven by the driving pulley 16. The solvent necessary for the extraction enters the hollow shaft 15 at 1'7 and 18, from which points it is conveyed through perforations 19 and 20 in the shaft into the interior of the drum in contact with the extraction material. 1

The extraction material introduced through the inlet funnel, a hopper 21 falls into the trough 22, where it is caught up by the screw conveyor on the shaft 15, and is thereby conveyed into the impregnating drum 1. The material is here continuously impregnated to the point of complete saturation with the solvent entering at 19, in such a way that the rotating drum 1 with its helical blades 9 constantly kneads the material under treatment and conveys the same to the second screw conveyor 24, situated on the shaft 15. This screw conveys the material through the constriction 25 between the drums 1 and 2 to the filtering and washing drum 2. The material is here also again Worked up by the helical blades 10, and is subjected to further repeated washing by the solvent issuing from the perforations 20.

The drum wall 2 constructed in the form of a filter 11 allows the solvent saturated with oil and fat (miscella) to fiow into the casing '7, from which it passes through the discharge pipe 8 to the distillation apparatus. Owing to the continuous rotation of the drum, the surface of the filter 11 as it comes to the top, is constantly freed afresh from the adhering extraction material, because the latter falls downwards owing to its own weight and the moisture contained therein is not absorbed by the impregnated silk. In this way constant and uniform permeability of the filter and a continuous operation are ensured.

The helical blades 10 pass the filter residue remaining in the drum 2 on to the screw conveyor 26 of the shaft 15, which conveys it to the discharge pipe 27. The residue leaving the apparatus at this point can, if desired, be again introduced into the extraction apparatus or to a further apparatus operating in the same manner in order to obtain as clear a filtrate as possible. Further several drums 2 may be connected one behind the other.

According to the modification illustrated in Figures 4 and 5, the drum 2 is divided into drum cells 30 by constrictions 28, into which the partitions 29 interlock. The material under treatment is introduced in the direction of flow of the arrow 31, whilst the solvent is introduced into the filter drum in the direction of the arrow 32. The apparatus therefore operates on the counter-current principle. The screw conveyor 10 of the individual cells conveys the material, in the manner hereinbefore described, from one cell to another through the constricted openings 33 between the cells. The solvent, which enters through the hollow shafi 5, fills the external drum 7 to a definite height, and flows through the overflows 34 situated in the partition walls 29 from one cell to the other, and finally passes through the discharge pipe 8 attached at 35 to the distillation plant in the form of 9;

highly saturated filtered miscella. By means of this modification the extraction material comes into particularly intimate contact with the solvent and consequently thorough washing is effected.

In a further modification the apparatus may consist only of a filter and washing drum such as the drum 2. In this case, the material must be introduced into the drum in a state of complete saturation with the solvent. The above described filtering and washing drum is then in itself a continuous operating filter.

After the extraction has been completed the discharged material may be subjectedin known manner to pressure in order to remove the greater portion of the solvent. The expulsion of the residual solvent is then effected in a continuous process by means of a suitable expelling appa ratus which follows immediately on the former. If desired a pressing out process may be inserted between the individual drum systems, so that repeated pressing is effected in known manner in combination with the extraction by means of the above described drum system.

What Iclaim is:

1. Apparatus for continuously extracting and filtering material containing a soluble substance by means of a solvent, comprising a rotatable impregnating drum wherein the material to be treated is impregnated with solvent and a rotatable washing and filtering drum rigidly connected in axial alignment with the impregnating drum, separate means for passing the raw material and solvent into said drums, and separate means for removing the resulting filtrate and residue from said drums, said filtering drum having a covering formed of impregnated moisture-proof silk.

2. Apparatus for continuous extraction and filtration of material containing a soluble substance comprising a rotatable drum provided with transverse constrictions forming compartments in series, at least one of said compartments being perforated, an independently rotatable conveyor means within said drum, means for producing a continuous flow of material under treatment through said compartments, means for continuously removing said material from the drum, and means for continuously. directing solvent through said material in the opposite direction to its flow.

3. Apparatus for continuously extracting and filtering material containing a soluble substance by means of a solvent, comprising an impregnating drum wherein the material to be treated is impregnated with a solvent and a rotatable washing and filtering drum rigidly connected with the impregnating drum, spiral conveyors fixed to the inner walls of said drums, said filtering drum having a wall pervious to the solvent and extract and a rotatable shaft extending through the drums, conveyor means on said shaft, means to rotate said shaft, separate means to rotate said drums, and means to regulate the speed of rotation of said shaft and drums.

4. An extracting and filtering apparatus comprising a rotatable impregnating drum for impregnating a material with a solvent, a rotatable washing and filtering drum rigidly connected in axial alignment with said impregnating drum, a constriction in said rigid connection, separate means for feeding the raw material and the solvent into said drums, and separate means for withdrawing the resulting filtrate and residue from said drums, said filtering drum having a wall pervious to the solvent and extract.

PHILIP? LORENZ FAUTH. 

